Inter Base Station Handover Method, Radio Communication System, Drx Control Method, Base Station, and Communication Terminal

1. A mobile station, comprising: a receiver configured to receive signals; and a controller configured to use at least one of a first Discontinuous Reception (DRX) configuration or a second DRX configuration having longer DRX cycle than a DRX cycle of the first DRX configuration, wherein the controller is further configured to start to use the second DRX configuration if the mobile station does not receive data within a predetermined period while using the first DRX configuration.

2. The mobile station according to claim 1 , wherein the controller is further configured to use at least one of the first and second DRX configuration in DRX operation during a Radio Resource Control (RRC) Connected state.

3. A method of a mobile station, the method comprising: receiving data; using at least one of a first Discontinuous Reception (DRX) configuration or a second DRX configuration having longer DRX cycle than a DRX cycle of the first DRX configuration, starting to use the second DRX configuration if the mobile station does not receive data within a predetermined period while using the first DRX configuration.

4. The method according to claim 3 , further comprising: using at least one of the first and second DRX configuration in DRX operation during Radio Resource Control (RRC) Connected state.